Step-by-step feed system for photocopying apparatus



H. MEY

Nov. 29, 1966 STEP-BY-STEP FEED SYSTEM FOR PHOTOCOPYING APPARATUS Filed March 9, 1964 2 Sheets-Sheet 1 H., MEY 3,288,046

2 Sheets-Sheet 2 STEP-BY-STEP FEED SYSTEM FOR PHOTOCOPYING APPARATUS Filed March 9, 1964 Nov. 29, 1966 United States Patent 3,288,046 STEP-BY-STEP FEED SYSTEM FOR PHOTO- COPYING APPARATUS Hansjuerg Mey, Oberengstringen, Switzerland, assignor to Gretag Aktiengesellschaft, Regensdorf, Switzerland Filed Mar. 9, 1964, Ser. No. 350,364 Claims priority, application Switzerland, Mar. 12, 1963, 3,155 63 5 Claims. (CI. 9575) This invention relates to a step-by-step feed system for photocopying apparatus adapted to work with copying material in strip form which can be moved forward, by means of a transport device which can be motor-driven, between exposure phases in a step-by-step manner, whereby the length of step is adjustable to conform with the size of the picture.

Great demands are made on intermittent feed systems of this kind, especially with regard to the precision of the adjusted length of advance, because any inaccuracy results in lack of symmetry in the edges of the picture, which can be very annoying even if the faults are only sliht.

The principle of methods which have already been proposed in copying apparatus is, as the paper is advanced, to measure off a constant, predetermined length of paper or a constant, predetermined feed time. The disadvantages of this method lie in the extensive mechanical and electrical means which are necessary, the not very good precision, and the complications and possibilities of error entailed in a change of the picture size.

The present invention seeks to obviate these disadvantages by providing a step-by-step feed system for a photocopying apparatus adapted to operate with copying material in strip form, wherein a feed system is provided for advancing the strip of copying material stepwise between exposure phases means being provided for adjusting the length of the step .to conform with the size of the picture, and wherein a marking device and a sensing device are disposed behind one another so as to lie at the edge of the strip of copying material, when present, the distance between such devices being adjustable to conform with the feed or the picture format required at any particular time, the arrangement being such that the feed system can be switched off by means of the sensing device, at least for the duration of the exposure. It is preferable if the marking and/ or sensing device is positively coupled with .the adjustable part of the mask aperture limits lying transversely in relation to the direction of advance of the strip.

Thus the essential idea of the present invention consists in the fact that a mark is made on the photo paper, preferably on the rear thereof at the entry side of the mask and at the exit side of the mask there is a receiving device which detects the passage of a mark. If the marking and receiving devices are correctly set in relation to the edges of the mask and if the paper advance is then interrupted when a mark arrives at the receiving device, the length of feed will automatically reach the correct value in every case, independently of the size of the mask aperture. When the aperture is changed care must be taken that the marking and receiving devices are shifted with the mask aperature margins lying transversely to the paper web and that this shifting is not carried out until the last mark of the old aperture size has been put on.

The marks which are made on the back of the paper for contnolling the feed can be utilized, when the roll has been developed, for cutting the roll automatically according to the sizes of the individual pictures. A receiving device like the one in the copying apparatus can be used in this cutting arrangement.

In a preferred embodiment the marking device is an ink printing device and the sensing device is a photoelectric detector. The printing is preferably eifected with a printing ink which absorbs at least the infra-red and the sensing can then be by means of infra-red light. The present photoelectric method of sensing gives the advantage of great simplicity and operational reliability. By the use of infra-red light all harmful influence of the photosensitive layer of the copying material is definitely eliminated.

Other distinguishing marks, such as, e.g., the number of the copying machine and the sign of the firm, can be printed at the same time as the marks.

In order to enable the invention to be more readily understood, reference will now be made to the accompanying drawings, which illustrate diagrammatically and by way of example an embodiment thereof, and in which:

FIG. 1 shows a schematic general view of a step-bystep feed system for a photocopying apparatus, and

FIGS. 2a to 2e represent a detail of the system and serve to explain the changing of format.

Referring now to FIG. 1, there is shown a step-by-step feed system, the actual feed mechanism of which is of a structural type known per se and consists essentially of a supply drum 1, a guide and pressure roller 2, a driving roller 3, a guide roller 4 and a take-up drum 5. The driving roller 3 can be driven intermittently by a motor 7. The motor 7 illustrated in the drawing is a stop motor. However, instead of this stop motor it would be possible to use a unit consisting of a motor of the usual construction and a magnetic clutch.

When the drive is switched on the driving roller 3 is rotated in the direction indicated by the arrow b, thus causing a strip of copying material 6 to be advanced from the supply drum 1 to the take-up drum 5 over .the rollers 2, 3, and 4 in the direction of the arrow a. During this process the strip 6 passes through a projection, or picture plane (picture window) disposed between the driving roller 3 and guide roller 4 and indicated by the distance arrow 11.

A mask 12 limits the picture aperture and has four limiting parts which are disposed in a rectangle and which are capable of adjustment according to the required size of picture. For this purpose the two parts 13 and v14, lying transverse to the direction of travel of the strip material and illustrated in section (shaded), can be shifted in the directions shown by the arrows h, i, j and k. The parts 13 and 14 are desirably coupled together in such a manner that, by the operation of a single control, they are always moved together in a direction towards, or away from each other so as to shorten, or lengthen respectively the length of the picture window 11 in the direction of travel of the strip of copying material.

The take-up drum 5 is motor driven through a friction clutch 9 in the direction of the arrow 0. For this purpose, as shown in the drawing, it is provided with its own motor 10; but it is also possible to derive the drive for the friction clutch from the driving motor 7 of the driving roller 3, preferably with the interposition of a transmission gear. The torque to be transmitted by the friction clutch 9 is adjusted in accordance with the resistance to motion of the picture aperture and the guide roller 4.

A marking device 20 and a sensing device 30 are provided for the control of the strip feed. In relation to the strip 6, the marking device 20 is disposed opposite the mask limiting part 13 on the entry side and the sensing device 30 is opposite the mask limiting part 14 on the exit side, so that as they run on, the individual strip positions pass the marking device 20 first and the sensing device 30 afterwards.

The marking and/or .sensing devices can be shifted in the directions indicated by the arrows d, e, f and g. A coupling provided between the marking and/ or sensing devices and the two adjustable parts 13 and 14 of the mask is indicated symbolically in FIG. 1 by the double lines between the arrows h and d, i and e, j and f, and k and g. This coupling can be effected by appropriate means of well-known type and hence has not been shown in detail in the drawing. Thus, the marking device is shifted up or down as mask part 13 is shifted up or down, and similarly, the sensing device is shifted up or down as mask part 14 is shifted up or down, so that the distance between the marking device 20 and sensing device 30 is increased or decreased, respectively as the picture window 11 is lengthened or shortened, respectively.

The marking device 20 is constructed as an ink printing device and the sensing device 30 is constructed as a photoelectric probe.

As can be seen from FIG. 1 the ink printing device consists, for example, of an electromagnet 21, the armature 22 of which carries a printing stamp 23. Between the printing stamp and the back of the strip of copying material 6 is an inked ribbon 24. When the electromagnet 21 is operated the stamp 23 strikes the inked ribbon 24 which consequently produces an ink mark M on the back of the copying material strip 6. The return movement of the stamp, or magnet armature, causes the inked ribbon stretched between rollers 25 and 26 to turn on a little, so that there is always fresh inked ribbon facing the stamp, or the back of the copying strip.

The photoelectric sensing device comprises a source of light 31 and a photo diode 32 with a front lens 33. These two elements are so disposed that the light radiated from the light source 31 on to the back of the copying material strip 6 and reflected therefrom reaches the photo diode 32. The photo diode and its front lens are so adjusted, that as a mark M passes by, an optimal current impulse is generated by the photo diode due to the reduction in light incidence (current drop impulse).

It is preferable for the printing to be carried out with a printing ink absorbing at least infra-red. In this case a filter 34 which is permeable to infra-red is arranged in front of the light source 31.

The current impulse delivered by the photo diode controls the transport mechanism through a switch amplifier 40. The output of the amplifier is connected with a stop brake 8 of the motor 7. The stop brake acts, on the occurrence of a current pulse (current drop impulse), to interrupt the feed of the strip 6.

The switch amplifier consists essentially of a relay 43 with two reversing contacts 45 and 46 operable by two transistors 41 and 44. The switch amplifier is connected to the marking device 20 by means of the reversing contact 45 through a starting device 50 and, by means of the reversing contact 46 and preferably through a delay mechanism 70, it is connected with the brake 8 of the stop motor 7.

The starting mechanism includes a starting key 51 and a resistance-capacitor combination 5352.

A current supply device is arranged to supply the switch amplifier with energy and to feed the sensing light source 31 and stop brake 8 through the relay contact 46, and to feed the exciting winding of the magnet 21 through the resistance-capacitor combination 53-52.

In the resting state and with the current supply switched on the two relay contacts 45 and 46 are in the position 1, which corresponds to the excited condition of the relay. The relay contact 45 is connected as a locking contact, through the key 51. The key 51 is likewise in its state of rest 1, so that the winding of the relay 43 is connected by way of the contact 45 and the key 51 to the supply voltage and remains energized. Hence in the resting condition the supply to the light source 31 is interrupted, the photocell 32 is without current, the transistor 41 is blocked and the transistor 44 is conductive.

When the starting key 51 is operated by being moved into the position 1', the locking circuit (6il43455160) of the relay 43 is interrupted. Simultaneously the printing magnet 21 receives a short pulse of current through the resistance-capacitor combination 53-52, whereupon the stamp 23 springs against the strip 6 and produces a mark M on the part of the strip which is in the range of the printing device. The release of the relay 43 causes the contacts 45 and 46 to come into their r positions. As a result, current is supplied to the light 31 and the stop motor 7 through the contact 46.

The transistor 41 is conductive, through the photocurrent of the photo diode, from the negative supply potential applied to the terminal 42. Thus the transistor 44 is blocked and the winding of relay 43 is without current.

Now, if one of the marks M comes within the sensing field 15 of the photo diode 32 as the strip is fed along, the field is darkened and the previously mentioned current drop impulse is produced. This impulse blocks the transistor 41 and opens the transistor 44. As a result, the relay 43 pulls up and its contacts 45 and 46 come back again into the 1 position. The supply of current to the stop motor 7 and the light 31 is cut off and the paper feed is stopped, the relay 43 being again in the locking condition. The feed and control system is then in its rest position once more, as a whole, and is ready for a fresh feed operation.

The strip 6 was thus advanced by a distance corresponding to the distance between the stamp 23 and the photo diode sensing point 15. Any overrunning of the mark beyond the predetermined point owing to sluggishness of the stopping mechanism can be prevented by an nature of a speed allowance device. To this end an adjusting device, which is not illustrated, is provided.

With the delay system 70, which is not illustrated in detail, it is possible if necessary to arrange that the feed 3 does not operate until a certain, preferably adjustable,

lapse of time after the mark has been applied and the lamp switched on. This is particularly advisable with high speeds of advance. The delay system prevents the strip from pulling away under the stamp prematurely,

' thereby causing the mark to smudge, and it ensures that the time taken by the advance step is shorter than the time required for the sensing lamp to warm up.

The switching arrangements were deliberately made so that the sensing lamp 31 is switched off while the system is in the resting condition. As a result the amount of light from the sensing device, and hence the action of light and heat on the copying material and photo diode, are reduced to a minimum.

The chosen circuit arrangement works without closedcircuit current transfer. The advantage of this is that the switching amplifier 40 can also be designed immediately as an alternating current amplifier. In the example shown it would only be necessary, essentially, to replace the galvanic couplings between the individual stages by condenser couplings.

An automatic control (not shown) can be provided for the release of the starting key 51, for example of such a type that the release is effected each time a picture exposure is completed. In this arrangement the period during which the starting key is thrown into its starting position (r) is always chosen to be shorter than the period for a step of the feed.

The adjustment for change of format is described in greater detail below, with reference to FIGURES 2a to 2e, in which the same references as in FIG. 1 are employed for the same parts.

FIG. 2a shows the state of the arrangement after exposure of a picture on to the strip but before actuation of the starting device. Here, the latent image is indicated by the thicker line 80. On operation of the key 51 (FIG.

1) the stamp 23 strikes the back of the strip 6 leaving on it a marking M (FIG. 2b).

As a variant from the above-described normal procedure, the process can be interrupted after a mark has been printed and a change of format can be undertaken. A special signal arrangement can be provided to indicate this situation.

As an example, in order to reduce the format the two parts 13 and 14 of the mask are pushed closer together. As a result of the above-described mechanical linkage between these mask portions and the marking and the sensing devices, this action causes the stamp 23 and the photo diode 32 to be moved closer together to the same extent. After this adjustment the mask parts 13 and 14, the stamp 23 and the photo diode 32 are in the position represented in FIG. 2c. The strip advance is now released and the strip runs until the mark M comes under the photo diode. The following step of the feed is therefore shortened by the same amount P by which the sensing element was shifted. It is now possible to expose a picture of smaller format. The latent image produced is indicated in FIGURES 2d and 2e by the thicker line 81. If a fresh starting command is now given a fresh mark M is applied to the strip and the latter is moved on in conformity with the newly adjusted mask aperture. Here, the step of the advance is shorter by the length 2P.

The distance between the individual pictures is independent of the adjustment of format so the cutting of the developed strip can be carried out by the feed marks without double cutting and loss of paper.

Instead of the ink printing system and the photoelectric sensing device it is also possible, naturally, to use other arrangements for marking and sensing. For example the marking device may be constructed in the form of a punch or a printing device for magnetically or electrically conducting substances. The sensing device would then, accordingly, be composed of a mechanical feeler or a magnetic pick-up or contact brush.

What is claimed is:

1. A step-by-step feed mechanism for photocopying apparatus adapted to operate with copying material in strip form, comprising an adjustable length masking device defining a correspondingly adjustable length picture aperture, roller guide means for guiding a strip of copying material in a plane parallel to the plane of said masking device adjacent said picture aperture and longitudinally thereof, said masking device including first and second parallel spaced parts lying transversely of the direction of travel of the copying material which establish the upper and lower sides of said picture aperture, said first and second parts being adjustable parallel to themselves to wards and away from each other to correspondingly shorten or lengthen said picture aperture in accordance with the requirements of a picture format, a marking device including means for making a mark on the copying material before the material enters said picture aperture, said marking device and said first part of said masking device being coupled together for movement as a unit as said first part is adjusted, a sensing device including means for detecting marks made on the copy material by said marking device after such marks leave said picture aperture, said sensing device and said second part of said masking device also being coupled together for movement as a unit as said second part is adjusted, a motor for driving said roller guide means thereby to move the copying material longitudinally past said picture aperture, and electrical control circuit means for controlling operation of said motor and marking device, said circuit means including means for momentarily actuating said marking device to make a mark on the copying material and for starting said motor to drive said marked copying material past said picture aperture, and means controlled by said sensing device and actuated upon arrival of the mark on the copying material at said sensing device for stopping said motor and hence also stopping the copying material.

2. A step-by-step feed mechanisms as defined in claim 1, wherein said electrical circuit means includes a switch amplifier.

3. A step-by-step feed mechanism as defined in claim 2, wherein said switch amplifier includes a relay, two reversing contacts to said relay and two transistors arranged to operate said relay.

4. A step-by-step feed mechanism as defined in claim 1, wherein said marking device is an electro-magnetic marking device operable from said electrical circuit means.

5. A step-by-step feed mechanism as defined in claim 4, wherein the marking device is an ink printing device employing a printing ink which absorbs at least infra-red, and the sensing device is a photoelectric sensing device which responds at least in the infra-red.

References Cited by the Examiner UNITED STATES PATENTS 2,349,941 5/1944 Cr-amwinckel et a1. 352-182 2,928,328 3/1960 Klein -75 2,948,207 8/1960 Amsel et a1. 95-75 FOREIGN PATENTS 1,133,239 7/1962 Germany.

JULIA E. COINER, Primary Examiner. 

1. A STEP-BY-STEP FEED MECHANISM FOR PHOTOCOPYING APPARATUS ADAPTED TO OPERATE WITH COPYING MATERIAL IN STRIP FORM, COMPRISING AN ADJUSTABLE LENGTH MASKING DEVICE DEFINING A CORRESPONDINGLY ADJUSTABLE LENGTH PICTURE APERTURE, ROLLER GUIDE MEANS FOR GUIDING A STRIP OF COPYING MATERIAL IN A PLANE PARALLEL TO THE PLANE OF SAID MASKING DEVICE ADJACENT SAID PICTURE APERTURE AND LONGITUDINALLY THEREOF, SAID MASKING DEVICE INCLUDING FIRST AND SECOND PARALLEL SPACED PARTS LYING TRANSVERSELY OF THE DIRECTION OF TRAVEL OF THE COPYING MATERIAL WHICH ESTABLISH THE UPPER AND LOWER SIDES OF SAID PICTURE APERTURE, SAID FIRST AND SECOND PARTS BEING ADJUSTABLE PARALLEL TO THEMSELVES TOWARDS AND AWAY FROM EACH OTHER TO CORRESPONDINGLY SHORTEN OR LENGTHEN SAID PICTURE APERTURE IN ACCORDANCE WITH THE REQUIREMENTS OF A PICTURE FORMAT, A MARKING DEVICE INCLUDING MEANS FOR MAKING A MARK ON THE COPYING MATERIAL BEFORE THE MATERIAL ENTERS SAID PICTURE APERTURE, SAID MARKING DEVICE AND SAID FIRST PART OF SAID MASKING DEVICE BEING COUPLED TOGETHER FOR MOVEMENT AS A UNIT AS SAID FIRST PART IS ADJUSTED, A SENSING DEVICE INCLUDING MEANS FOR DETECTING MARKS MADE ON THE COPY MATERIAL BY SAID 